Micropumps are devices that can pump and valve small volumes of fluids. A number of micropumps have been demonstrated, many of them diaphragm pumps utilizing check valves and piezoelectric actuation. Some of these micropumps have demonstrated low power consumption and reasonable flow rates, but out-of-plane fluid flow may be necessary due to the absence of a good planar fluid flow check valve for such micropumps.
Some of these micropumps use semi-flexible membranes to pump fluid in and out of chambers having angular profiles. Such micropumps may exhibit leakage, backflow, and dead volume due to a mismatch between the shapes of the membrane and the chamber. Dead volume refers to a volume of fluid that is not displaced in the pump during a pumping cycle.